Define probable cause. Explain who determines whether probable cause to arrest exists.

Probable cause is defined as existing if there is a substantial likelihood that (1) a crime was committed and (2) that the individual committed the crime. Whether probable cause to arrest exists is determined by the police, if the crime is committed in their presence. If a victim or some other person reports a crime to the police, the police must decide whether there is enough information about the alleged wrongdoer's guilt to establish probable cause to arrest. If the police try to gather information to help them determine whether a suspect should be arrested and, after investigating the matter decide to arrest the suspect, the police must obtain an arrest warrant from a judge or other public official.